Terpene derivatives



Patented Aug. 20, 1946 2,406,106. TERPENE DERIVATIVES Alfred L. Rummelsburg, Wilmington,

or to Hercules Powder Company, Del., a corporation of Delaware Application December 8, 1943,

Serial No. 513,483 a 1 Claims. (01. 260-617),

No Drawing.

This invention relates to a new series of terpene derivatives and more particularly to a new series of terpene derivatives resulting from the hydrogenation of condensation products of acyclic terpenes having three double bonds per molecule and acrolein. It also relates to a method for the preparation of these derivatives.

By the method in accordance with this invention, a condensation product of an acyclic terpene having three double bonds per molecule and acrolein is reacted with hydrogen. In this manne there is obtained a, cyclic primary alcohol which may or may not be saturated depending upon the conditions under which the hydrogenation reaction is carried out.

A condensation product of acrolein and-an acyclic terpene having three double bonds per molecule as, for example, allo-ocimene, ocimene, myrcene, cryptotaenene, etc., is first prepared. This condensation product is then hydrogenated Del., assign- Wilmington,

- from the first and second fractions was hydroto form a primary alcohol. Hereinafter, in this specification an acyclic terpene having three double bonds per molecule will be referredto for convenience as an acyclic terpene. I The method in accordance with" this invention is illustrated by the examples which follow. All parts and percentages are by weight unless otherwise specified.

Example 1 A condensate of myrcene and acrolein was prepared by heating a mixture containing 80 parts Percent comb ned acrolein as v acrolein Fraction ggfiggft Yield, parts 71 (pale liquid) 13 (pale liquid) 10 (viscous resin) Residue Calculated percentage of combined aldehyde as acrolein for a condensate containing one mole acrolein per mole of myrcene is 29.3 2

genated in, the presence of 1.6v parts copper chromite catalyst in a stainless steel autoclave. The contents were heated under pressure. inaccordance with the following schedule: f

-' Tempera- Pressure, Tune hours ture, 0. lb. per sq. in.

Start 28 2, 000 1 180 1, 960 180 1, 775 180 1, 740 180 l, 740 27 1, 225

The hydrogenated material was removed fromv the autoclave and diluted with ethyl alcohol. The catalystrwas removed fromtheproduct by filtration and the filtrate was distilled at 18mm. to a bath temperature of 100 C. to remove the alcohol. The residue was distilled at 1 mm. pressure to a bath' temperature of 165 C. Nineteen parts of distillate, which was a nearly colorless oil, was obtained. This product was analyzed with the following results:

(14 n 1.4910 Per cent OH (by acetyla-tion) 8.6 (theory 8.75)

Example 2 Twenty-five parts of myrcene-acrolein condensate, prepared by the method described in Example 1,,were mixed with 5.2 parts Raney nickel catalyst which had previously been washed with isopropyl alcohol. The condensate was then hydrogenated in a stainless steel autoclave. The contents were heated under pressure according to the following schedule:

Time, hours Pressure, lb. per sq. in.

About 2.90% hydrogen by weight was absorbed.

Twenty-five parts myrcene-acrolein condensate .The theoretical amount of hydrogen for therenot from the catalyst. at 18 mm. to a bath temperature of 100 C. to remove traces of isopropyl alcohol. The residue ;Was a nearly colorless oil having the following under a nitrogen atmosphere to 175 1 hours, then. cooled to j mixture was distilled at '18 mm. to a bath tern- 1 perature of 130 Distillation was continued at 1 mm. The follow- 'ing table shows the results of the distillation:

V theoretical amount of propyl alcohol prior to use.

duction of the aldehyde and the hydrogenation of two double bonds is 3.12%.

The mixture was filtered to separate the prod- The filtrate was distilled characteristics:

Per cent on (by acetylation) 8.4 (theory 8.6%) 7 Example 3 A mixture containing 80 parts allo-ocim ene (d4 0.8139, n 1.5417), 1 0.5 part tert-butyl catechol (to inhibit polymer- 50 parts acrolein, and

ization) was heated in a stainless steel autoclave C. for 6 room temperature. "The C., to remove excess acrolein..

Percent Vapor Fraction temperature, gi g gf figtfi acrolein The calculated percentage of combined aldehyde as acrolein for a condensate containing one mole allo-ocimene per mole acrolein is 29.1%.

Twenty-five parts of allo-ocimene-acrolein condensate. from the first fraction was hydrogenated in the presence of 1.6 parts of a copper chromite catalyst in a stainless steel autoclave. The contents were heated under pressure according to the following schedule.

Time, hours gf g t a 53 55355? Start 30 2, 000 180 1, 940

Example 4 Twenty-five parts of allo-ocimene-acrolein condensate from the first fraction of Example 3, were hydrogenated. in the presence of 5.2 parts Raney nickelcatalyst, which had been washedwith iso- The hydrogenation example, the acyclic terpenes 4 was carried out in a stainless steel autoclave according to the following schedule:

800 (H2 added 1:0 2,000 1,925.

About 3.38% hydrogen was absorbed. The

i 7 mixture was filtered to separate the catalyst. The

filtrate was distilled at a pressure of 16 mm. to a bath temperature of isopropyl alcohol. The yield was 13.1 parts of nearly colorless oil having the following characteristics: 1

Per cent OH (by acetylation) 8.4 (theory 8.6)

Example 5 Twenty parts of allo-ocimene-acrolein condensate from the first fraction of Example 3 are mixed with 10 parts of isopropyl alcohol as a solvent and then hydrogenated in the presence of 5 parts of Adams platinumoxide catalyst in a Parr shaker. The contents were heated at 40-55" C. at a pressure of 30-55 lbs. per sq. in. for

6 hours. About 3.2% of hydrogen was absorbed after correcting for that required to reduce the platinum oxide. The mixture was filtered to remove the catalyst. The filtrate was distilled at a pressure of 16 mm. to a bath temperature of 100 C. in order to remove the solvent. The resulting colorless oil had thefollowing characteristics:

' tion product of an acyclic terpene hydrocarbon having theformula C10H1e with acrolein i5 hydrogenated. in the presence of a catalyst. For

operable in accordance with the invention include allo-c-cimene, myrcene, ooimene, and cryptotaenene. The acyclic terpenes may be used either in pure form or mixed with other substances.

r The condensation product of an acyclic terpene with acrolein is obtained by heating an acyclic'terpene with acrolein. The major portion of condensate results-from a Diels-Alder reaction between the acyclic terpene and acrolein and are unsaturated cyclic tion to the Diels-Alder reaction, in which one molecule of acrolein adds to one molecule of an acyclic .terpene, other types of reaction may occur, for. example; two molecules of acrolein may react with one molecule of the terpeneor vice versa. The extent to which each of these reaction takes place will depend upon the relative proportions of the reactantsand the conditions of the reaction. Furthermora'during this condensation any of the above condensation products or reactants may polymerize. It is desirable to add a polymerization inhibitor, suchfasterfte butyl 'catechol, phenyl-beta-naphthylamine,- etc., in order to hinder the formation of polymerized products. The compound dominate in the mixture will be thatiormed when one molecule-of acyclic terpene condenses with one molecule oracrolein, particularly so C. to remove traces of aldehydes. In addi-,

which will greatlyprea when the latter is used in slight excess. This same compound can, if desired, be separated from the other constituents by vacuum distillation, or the crude condensate may be'reduced as such.

, The condensation products from the above procedure are viscous yellow liquids. The product resulting from the addition of one molecule of acrolein to one molecule of allo-ocimene may be referred tov as dimethyl(butenyl)tetrahydrobenzaldehyde and the product resulting from the addition of one molecule of acrolein to one molecule of myrcene may be referred to as isohexenyl tetrahydrobenzaldehyde. If desired, the crude condensate may be employed in the process of the invention, as may any of the compounds separable therefrom.

To form a cyclic primary alcohol, in accordance with my invention, any'oi" the aforesaid condensation products of acyclic terpenes with acrolein may be reduced by hydrogen either with or without the use of a suitable hydrogenation catalyst. Preferably, the condensate resulting when equimo ar proportions of the reactants are combined will be employed. It is however, preferable to use a catalyst inasmuch as greater selectivity is thereby obtainable. It is possible, by the use of a particular catalyst, as hereinafter described, to hydro enate only the aldehyde grou of the condensate molecule. If only the aldehyde group is reduced. the product is a substitution product of tetrahydrobenzaldehyde. For example. it is believed that dimethyl(butenyl)tetrahydrobenzaldeh de forms dimethyl(butenyl)tetrahydrobenzyl alcohol, isohexenyl tetrahydrobenzaldehyde forms isohexenyl tetrahydrobenzyl alcohol. On the other hand, certain catalysts in conjunction with the use of relatively high'conditions of temperatures and pressure, lead to the hydrogenation of the ethylen c bouble bonds of the molecule as well as the aldehyde group; It is believed that the products of this hydrogenation are substitution products of hexahydrobenzyl alcohol; for example, dimethyl(butvDhexahydrobenzyl alcohol and isohexyl 'hexahydrobenzyl a1- cohnl.

Without regard to selectivity, the operable catalysts which may be used are active hydrogenation catalysts, and include active copper chromite catalyst, the base metal catalysts. such as active nickel. Raney nickel, etc.. the noble metal catalysts such as active platinum, palladium, rhodium, osmium. iridium. and ruthenium. The quantity of catalyst, may vary up to about of they weight of the acyclic terpene-crotonaldehyde condensate, preferably up to about 5.0%. The foregoing catalysts may be used in unsupported form, or, if desired, supported on suitable inert support materials, such as kieselguhr, diatomaceou earth, activated clay, etc. The hydrogenation is desirably carried outat temperatures ranging from about 25 C. to about 250 C., and at a pressure of lbs. per sq. in. to 3000 lbs.

'per sq. in., depending upon the catalyst and the degree of hydrogenation desired. Using active base metal or copper chromite catalysts the preferable pressure range is from about 250 to about 3000 lbs. per sq. in., and the preferabletemperatures range from about 100 C. to about 200 C. Using active noble metal catalysts, the preferable pressure range is from about 15 lbs. per sq. in. to about 100 lbs. per sq. in., and the preferable temperature range from about C. to about 100 C. Hydrogenation is continued until the desired degree of absorption has occurred and mayv operable and preferred ranges for this catalyst,

as disclosed above, in most cases the aldehyde group is preferentially hydrogenated and an'unsaturated alcohol results. On the other hand,

the use of active noble or base metal catalysts, in particular, active nickel, platinum, or pal-.

ladium catalysts, under conditions of temperature and pressure within the operable and preferred ranges for these catalysts a previously given, results in hydrogenation of both the ethylenic double bonds and the aldehyde group and saturated alcohols result. In between these two extremes varying degrees of selectivity may be obtained using varied conditions of temperature and pressure, and using other catalysts under varied conditions.

After hydrogenation, the catalyst is removed in any desirable manner preferably by means of filtration. The solvent, if any is present, is removed by distillation. The product may then, if desired, be purified by means of distillation, preferably vacuum distillation. In this Way any polymeric alcohols, which may be present in small amounts, may be separated from the lower boiling monomeric alcohols. These polymeric alcohols comprise products formed during the hydrogenation, particularly, at high temperatures. For example, the condensates of one molecule of acrolein per molecule of acyclic terpene may polymerize and the polymer may then react with hydrogen to form an alcohol. It is, possible, too, that the monomeric alcohol may first form, followed by polymerization. The monomeric alcohols are liquids, Whereas the polymeric alcohols are soft resins.

In addition, if, for example; an acyclic terpeneacrolein condensate, which does not consist entirely of the condensate which is formed from one molecule of acyclic terpene per molecule of acrolein, is used in the hydrogenation, alcohols formed upon hydrogenation may be separated by vacuum distillation.

This process of vacuum distillation will enable, in addition, the separation of any polymers of condensation products of acyclic terpenes and acrolein, which may have been present originally or which may have been formed during the hydrogen-aition. The probability is, however, that this polymerized condensate will ultimately be hydrogenated and be separated from the monomeric alcohols as a polymeric alcohol residue. Vacuum distillation is also efi'ective in separating color bodies if they are present in the crude hydrogenation product.

If desired, a suitable solvent may be employed during the hydrogenation process. Such solvent may be polar or non-polar in nature and may comprise saturated alcohols, such as methanol, ethanol, propanol, isopropanol, butanol, etc.; ethers such as ethyl ether, isopropyl ether, dioxane, etc.; esters such as ethyl acetate, butyl acetate, etc.; saturated hydrocarbons, such as gasoline, hexane, cyclohexane, petroleum ether, etc.; organic acids, such as acetic acid, propionic acid, butyric acid,.etc. If an organic acid is employed as the solvent, it is preferable to use it in conjunction with noble metal catalysts. The

3 solvent maybe-removed following separation; of" the catalyst, by means of distillation, preferably in vacuo. Asan alternative procedure; inaccordance-withfithe invention,- any of the acyclici ac'rolein condensates may be hydrogenated byv In "general; this i methodis less satisfactory than that of catalytic Reducing agents whichmay he means or a nascent hydrogen.

hydrogenation. employed when nascent hydrogen is employed include sodium am'algam dilute acid, 'zinc dustglacial acetic acid, sodium and ethyl alcohol, etc,

' usingftemperatures or froin240 "C. to 150 In;

general, these reducing agents are selective for the aldehyde group, the ethylenic double bonds remaming substantially unhydrog'enated.

The-alcohols produced hyvirtu'e of this invention are useful in the manufacture of various esters from which can be made insecticides, etc.,;

and in the manufacture of resins by sterification with monoor poly-basic acids. They may be sulfonated to 7' produce emulsifying, wetting, and

suusing agents which are used in the form ofv their 'alkaltand organic b ase salts. The monomeric alcohols themselves possess wetting and etergent properties when emulsified in water. This application constitutes a continuation-1m part of my application for U. '8. Letters Patent, senators. 396,216, fil'e'd May 31, 1"941.' i I What 1 claim and desire to protect by Letters Patent is:

1; Dimetnyllbutyl)hexahydrobenzyl alcohol. '2. Isohexyl henahydroben'z'yl alcohol.

s. The method 'or-produei' e a primary alcohol rrom a condensat on productcr an acyclic terpeir nevi gthree double bonds pe'r'molecule with acme-m. "'hi'ch comprises hydroge'nating said condensation product in co tact With anactive hydrogenation cfatal'yst. '4. The met odof producing apr'imary alcohol from a etude-seamen; product of an acyclic ter one having three double bonds per molecule with aerolein, "which com rises liydi'ogenatin'g said condensation product in contact'w'ith an active h'ase metal hydrogenation catalyst.

' 15. methodof roducing a primary alcohol 1 from a condensation product of acyclic ter pene having three-doublebonds per molecule withacrolein, which comprises hydrogenating said;

condensation product in contact with an active noble metal hydrogenation catalyst.

6. The method of producing a primaryalcohol from a condensation product of an acyclic tersquare inch.-

-8. The method of producing a primary alcohol from a condensation product of w an acyclic tor-- 'pene having three doublebonds permolecule with acrolein, which comprises hydrogeneting 'said condensation product in contact with an active noble metal catalyst-at a-temperatureof-irom about 25 C. to -about 100 (L-and at @a pressure of from about 15 lbs. per square-inch to about 100 lbs. per square inch 9. The method of producing a-primary alcohol.

from a condensation product of an acyclic tenpen-e havingthree double bonds per molecule acrolein, which comprises hydrogenatingsaid condensation product in contact with annacti-ve copper chromite catalyst at a temperature of immanent-100 (2.: to about 200 G. and at a pressure of from aboutozo lbs. per square inch to about 3000 lbs-per square inch. J

10-; As a new product a substitutedhydrobenzyl alcohol selected from the group consisting of dimethyl(butylbhexahydrobenzyl alcohol-, isohexa enyl tetrahydrobenzylalcohol and isohex l hexae hydrobenzylalcohol.

ALFRED L. RUMMELSHJBHURQQ 

